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Markers on Eye Diagrams IC615 vs IC514

miscrms

Can anyone tell me how to place markers on an eye diagram in IC615? 

We used to do this routinely in IC514 using the eyeDiagram() function in the calculator to plot the wrapped data and then using the a and b markers to make various measurements (amplitude, overshoot, jitter, rise/fall time etc).  The marker/cursor would automatically hop to whatever trace you put the mouse over as expected.  In IC615 we have tried using eyeDiagram() from calculator and the Measurements -> Eye Diagram tool from the plot window with the same result for both.  The markers will only snap on the first trace (data from 0 to the first wrap period interval), not the additional wrapped eye diagram traces. 

For example, for the plot "eyeDiagram(VT("/out") 2n 17n 120p)" the tracking cursor as well as any of the markers will only show values along the trace data from 0-120ps which is not even part of the displayed waveform as we're omitting all the data prior to 2ns.

Thanks,

Rob

  • Rob,

    Which subversion are  you using? There were some issues with markers on eye diagrams in early IC615 ISRs, but from my tests just now in ISR9 (the latest hotfix - 6.1.5.500.9) the markers (added with the "m" bindkey or a-b markers with the "a" or "b" bindkeys) work correctly and snap to any of the folded periods. The tracking cursor works OK too.

    Regards,

    Andrew.

  • And whilst I'm at it, the eye diagram assistant makes plotting eye diagrams and gathering statistics on it easier (there may be other things you want, so please contact customer support if you do). You can read my application note on the eye diagram if you're interested.

    Regards,

    Andrew.

  • Hi Andrew, thanks for the reply.  We are running IC6.1.5.500.2, so that sounds pretty likely to be our issue.  We'll try a more up to date subversion.  I will check out the application note, thanks for including the link!

    Rob

  • Going to 6.1.5.500.9 does indeed seem to have fixed the marker issue.  Unfortunately we seem to be having a new problem on this version.  After running a sim, upon trying to plot or refresh a differential trace I get the an error I haven't seen before:

    expression evaluation failed: Cannot get value from token.
    No valid waveforms for plotting

    Plotting either of the two signals we're trying to take the difference of works fine, and we had never seen this behavior in 6.15.500.2 for the same sim/signals.  Whats even wierder is that usually if I wait 5-10 min and try plotting again (without resimming) it works.  Any thoughts?

  • FYI I seem to be getting the same error when trying to plot an ac trace.  It works if I use the result browser from within the plot tool to select the net, or if I use the ADE results->direct plot->main form ->ac voltage magnitude, but if I use the calculator, or ADE results->direct plot->AC Magnitude or results->direct plot->main form ->ac voltage db20 I get the same error:

    expression evaluation failed: Cannot get value from token.
    No valid waveforms for plotting

  • One more data point, after sitting overnight I am able to plot the above ac traces that were not working shortly after the sim was run.  I did monitor the file size of the "psf/ac.ac" file on disk and it has not changed since immediately after the sim was run, so I don't think its a matter of waiting for the data to get written to disk which was the only explanation I could think of.

    Thanks,

    Rob

  • Rob,

    I thought I'd replied to this - there have been a few reports of this (even in the latest hotfixes), and they mostly seem to be due to problematic file servers which are not making the data visible on a networked machine quickly enough - I've seen a few cases with NFS caching in the past which have similar problems. There is a current set of CCRs on this - I would advise contacting customer support on this.

    Regards,

    Andrew,

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